<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Db
 * @subpackage Adapter
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Ibm.php 23775 2011-03-01 17:25:24Z ralph $
 */

/** @see Zend_Db_Adapter_Pdo_Abstract */
require_once 'Zend/Db/Adapter/Pdo/Abstract.php';

/** @see Zend_Db_Abstract_Pdo_Ibm_Db2 */
require_once 'Zend/Db/Adapter/Pdo/Ibm/Db2.php';

/** @see Zend_Db_Abstract_Pdo_Ibm_Ids */
require_once 'Zend/Db/Adapter/Pdo/Ibm/Ids.php';

/** @see Zend_Db_Statement_Pdo_Ibm */
require_once 'Zend/Db/Statement/Pdo/Ibm.php';

/**
 * @category   Zend
 * @package    Zend_Db
 * @subpackage Adapter
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Db_Adapter_Pdo_Ibm extends Zend_Db_Adapter_Pdo_Abstract {
	/**
	 * PDO type.
	 *
	 * @var string
	 */
	protected $_pdoType = 'ibm';
	
	/**
	 * The IBM data server connected to
	 *
	 * @var string
	 */
	protected $_serverType = null;
	
	/**
	 * Keys are UPPERCASE SQL datatypes or the constants
	 * Zend_Db::INT_TYPE, Zend_Db::BIGINT_TYPE, or Zend_Db::FLOAT_TYPE.
	 *
	 * Values are:
	 * 0 = 32-bit integer
	 * 1 = 64-bit integer
	 * 2 = float or decimal
	 *
	 * @var array Associative array of datatypes to values 0, 1, or 2.
	 */
	protected $_numericDataTypes = array (Zend_Db::INT_TYPE => Zend_Db::INT_TYPE, Zend_Db::BIGINT_TYPE => Zend_Db::BIGINT_TYPE, Zend_Db::FLOAT_TYPE => Zend_Db::FLOAT_TYPE, 'INTEGER' => Zend_Db::INT_TYPE, 'SMALLINT' => Zend_Db::INT_TYPE, 'BIGINT' => Zend_Db::BIGINT_TYPE, 'DECIMAL' => Zend_Db::FLOAT_TYPE, 'DEC' => Zend_Db::FLOAT_TYPE, 'REAL' => Zend_Db::FLOAT_TYPE, 'NUMERIC' => Zend_Db::FLOAT_TYPE, 'DOUBLE PRECISION' => Zend_Db::FLOAT_TYPE, 'FLOAT' => Zend_Db::FLOAT_TYPE );
	
	/**
	 * Creates a PDO object and connects to the database.
	 *
	 * The IBM data server is set.
	 * Current options are DB2 or IDS
	 * @todo also differentiate between z/OS and i/5
	 *
	 * @return void
	 * @throws Zend_Db_Adapter_Exception
	 */
	public function _connect() {
		if ($this->_connection) {
			return;
		}
		parent::_connect ();
		
		$this->getConnection ()->setAttribute ( Zend_Db::ATTR_STRINGIFY_FETCHES, true );
		
		try {
			if ($this->_serverType === null) {
				$server = substr ( $this->getConnection ()->getAttribute ( PDO::ATTR_SERVER_INFO ), 0, 3 );
				
				switch ($server) {
					case 'DB2' :
						$this->_serverType = new Zend_Db_Adapter_Pdo_Ibm_Db2 ( $this );
						
						// Add DB2-specific numeric types
						$this->_numericDataTypes ['DECFLOAT'] = Zend_Db::FLOAT_TYPE;
						$this->_numericDataTypes ['DOUBLE'] = Zend_Db::FLOAT_TYPE;
						$this->_numericDataTypes ['NUM'] = Zend_Db::FLOAT_TYPE;
						
						break;
					case 'IDS' :
						$this->_serverType = new Zend_Db_Adapter_Pdo_Ibm_Ids ( $this );
						
						// Add IDS-specific numeric types
						$this->_numericDataTypes ['SERIAL'] = Zend_Db::INT_TYPE;
						$this->_numericDataTypes ['SERIAL8'] = Zend_Db::BIGINT_TYPE;
						$this->_numericDataTypes ['INT8'] = Zend_Db::BIGINT_TYPE;
						$this->_numericDataTypes ['SMALLFLOAT'] = Zend_Db::FLOAT_TYPE;
						$this->_numericDataTypes ['MONEY'] = Zend_Db::FLOAT_TYPE;
						
						break;
				}
			}
		} catch ( PDOException $e ) {
			/** @see Zend_Db_Adapter_Exception */
			require_once 'Zend/Db/Adapter/Exception.php';
			$error = strpos ( $e->getMessage (), 'driver does not support that attribute' );
			if ($error) {
				throw new Zend_Db_Adapter_Exception ( "PDO_IBM driver extension is downlevel.  Please use driver release version 1.2.1 or later", 0, $e );
			} else {
				throw new Zend_Db_Adapter_Exception ( $e->getMessage (), $e->getCode (), $e );
			}
		}
	}
	
	/**
	 * Creates a PDO DSN for the adapter from $this->_config settings.
	 *
	 * @return string
	 */
	protected function _dsn() {
		$this->_checkRequiredOptions ( $this->_config );
		
		// check if using full connection string
		if (array_key_exists ( 'host', $this->_config )) {
			$dsn = ';DATABASE=' . $this->_config ['dbname'] . ';HOSTNAME=' . $this->_config ['host'] . ';PORT=' . $this->_config ['port'] . // PDO_IBM supports only DB2 TCPIP protocol
			';PROTOCOL=' . 'TCPIP;';
		} else {
			// catalogued connection
			$dsn = $this->_config ['dbname'];
		}
		return $this->_pdoType . ': ' . $dsn;
	}
	
	/**
	 * Checks required options
	 *
	 * @param  array $config
	 * @throws Zend_Db_Adapter_Exception
	 * @return void
	 */
	protected function _checkRequiredOptions(array $config) {
		parent::_checkRequiredOptions ( $config );
		
		if (array_key_exists ( 'host', $this->_config ) && ! array_key_exists ( 'port', $config )) {
			/** @see Zend_Db_Adapter_Exception */
			require_once 'Zend/Db/Adapter/Exception.php';
			throw new Zend_Db_Adapter_Exception ( "Configuration must have a key for 'port' when 'host' is specified" );
		}
	}
	
	/**
	 * Prepares an SQL statement.
	 *
	 * @param string $sql The SQL statement with placeholders.
	 * @param array $bind An array of data to bind to the placeholders.
	 * @return PDOStatement
	 */
	public function prepare($sql) {
		$this->_connect ();
		$stmtClass = $this->_defaultStmtClass;
		$stmt = new $stmtClass ( $this, $sql );
		$stmt->setFetchMode ( $this->_fetchMode );
		return $stmt;
	}
	
	/**
	 * Returns a list of the tables in the database.
	 *
	 * @return array
	 */
	public function listTables() {
		$this->_connect ();
		return $this->_serverType->listTables ();
	}
	
	/**
	 * Returns the column descriptions for a table.
	 *
	 * The return value is an associative array keyed by the column name,
	 * as returned by the RDBMS.
	 *
	 * The value of each array element is an associative array
	 * with the following keys:
	 *
	 * SCHEMA_NAME      => string; name of database or schema
	 * TABLE_NAME       => string;
	 * COLUMN_NAME      => string; column name
	 * COLUMN_POSITION  => number; ordinal position of column in table
	 * DATA_TYPE        => string; SQL datatype name of column
	 * DEFAULT          => string; default expression of column, null if none
	 * NULLABLE         => boolean; true if column can have nulls
	 * LENGTH           => number; length of CHAR/VARCHAR
	 * SCALE            => number; scale of NUMERIC/DECIMAL
	 * PRECISION        => number; precision of NUMERIC/DECIMAL
	 * UNSIGNED         => boolean; unsigned property of an integer type
	 * PRIMARY          => boolean; true if column is part of the primary key
	 * PRIMARY_POSITION => integer; position of column in primary key
	 *
	 * @todo Discover integer unsigned property.
	 *
	 * @param string $tableName
	 * @param string $schemaName OPTIONAL
	 * @return array
	 */
	public function describeTable($tableName, $schemaName = null) {
		$this->_connect ();
		return $this->_serverType->describeTable ( $tableName, $schemaName );
	}
	
	/**
	 * Inserts a table row with specified data.
	 * Special handling for PDO_IBM
	 * remove empty slots
	 *
	 * @param mixed $table The table to insert data into.
	 * @param array $bind Column-value pairs.
	 * @return int The number of affected rows.
	 */
	public function insert($table, array $bind) {
		$this->_connect ();
		$newbind = array ();
		if (is_array ( $bind )) {
			foreach ( $bind as $name => $value ) {
				if ($value !== null) {
					$newbind [$name] = $value;
				}
			}
		}
		
		return parent::insert ( $table, $newbind );
	}
	
	/**
	 * Adds an adapter-specific LIMIT clause to the SELECT statement.
	 *
	 * @param string $sql
	 * @param integer $count
	 * @param integer $offset OPTIONAL
	 * @return string
	 */
	public function limit($sql, $count, $offset = 0) {
		$this->_connect ();
		return $this->_serverType->limit ( $sql, $count, $offset );
	}
	
	/**
	 * Gets the last ID generated automatically by an IDENTITY/AUTOINCREMENT
	 * column.
	 *
	 * @param string $tableName OPTIONAL
	 * @param string $primaryKey OPTIONAL
	 * @return integer
	 */
	public function lastInsertId($tableName = null, $primaryKey = null) {
		$this->_connect ();
		
		if ($tableName !== null) {
			$sequenceName = $tableName;
			if ($primaryKey) {
				$sequenceName .= "_$primaryKey";
			}
			$sequenceName .= '_seq';
			return $this->lastSequenceId ( $sequenceName );
		}
		
		$id = $this->getConnection ()->lastInsertId ();
		
		return $id;
	}
	
	/**
	 * Return the most recent value from the specified sequence in the database.
	 *
	 * @param string $sequenceName
	 * @return integer
	 */
	public function lastSequenceId($sequenceName) {
		$this->_connect ();
		return $this->_serverType->lastSequenceId ( $sequenceName );
	}
	
	/**
	 * Generate a new value from the specified sequence in the database,
	 * and return it.
	 *
	 * @param string $sequenceName
	 * @return integer
	 */
	public function nextSequenceId($sequenceName) {
		$this->_connect ();
		return $this->_serverType->nextSequenceId ( $sequenceName );
	}
	
	/**
	 * Retrieve server version in PHP style
	 * Pdo_Idm doesn't support getAttribute(PDO::ATTR_SERVER_VERSION)
	 * @return string
	 */
	public function getServerVersion() {
		try {
			$stmt = $this->query ( 'SELECT service_level, fixpack_num FROM TABLE (sysproc.env_get_inst_info()) as INSTANCEINFO' );
			$result = $stmt->fetchAll ( Zend_Db::FETCH_NUM );
			if (count ( $result )) {
				$matches = null;
				if (preg_match ( '/((?:[0-9]{1,2}\.){1,3}[0-9]{1,2})/', $result [0] [0], $matches )) {
					return $matches [1];
				} else {
					return null;
				}
			}
			return null;
		} catch ( PDOException $e ) {
			return null;
		}
	}
}
